Inlet baffle for water heater

ABSTRACT

A baffle for slowing the incoming water flow into a booster heating tank so that the turbulence in the water tank is minimized. The baffle consists of an inner cap and outer cap which are positioned over the inlet to a water heating tank. The outer cap is spaced apart from the inner cap such that the incoming water flows through openings in the inner cap and is directed to the underside of the outer cap. The water, having been sufficiently slowed by the contact with the underside of the outer cap, then smoothly flows downward along the outer cap flange and into the main plenum of the tank.

BACKGROUND OF THE INVENTION

This invention relates to liquid heating and storage tanks, and moreparticularly to a baffle for use in connection with the water inlet forsuch a heating and storage tank. More particularly, the baffle of thepresent invention may preferably be used in connection with known waterboosters of the type that are used to raise the temperature of water toa desired level for use by a downstream user, generally a commercialwarewashing apparatus. The use of the baffle of the present inventionwith these types of boosters increases the heating efficiency of thebooster, thereby lowering energy usage and costs for the user, lowersthe time required to heat the water to the desired temperature, andhelps to provide water to the downstream user at a consistenttemperature.

Warewashing apparatuses, such as conveyor and batch type warewashing ordishwashing machines, generally receive water at a temperature of around110° from the central hot water supply of most buildings and houses.However, in order to comply with health regulations, warewashing systemsthat do not utilize a sodium hypochlorite sanitizing system or the likeare required to sanitize the ware being washed with a rinse using aminimum of 180° F. water. Furthermore, the use of a 180° F. water rinseis desirable because it facilitates the drying of the ware, therebydecreaseing the turnaround time necessary for reuse. This hightemperature is generally out of the range available from most buildingsand houses central hot water source. Thus, in order to supply water atthis desirable temperature, boosters have been employed to raise thetemperature of the incoming water from between 110° F. to the requiredsanitizing temperature of 180° minimum. However, with respect to thesebooster type heaters, research has shown that a relatively standardwater tank having a heater positioned in a center thereof developsstratified temperature gradients within the tank based upon the locationof the heater. This research has shown that the water above the heatertends to be hotter than the water below the heater. Accordingly, inorder to use the least amount of energy to heat only the water needed tothe required temperature at the time it is needed for the next washingcycle, it is desirable to use only this hotter “uper portion” of thewater for each rinsing cycle, thereby allowing the cooler “lowerportion” of the water to be raised up by the incoming water and heatedfor the next cycle.

In trying to take advantage of this stratified temperature gradient,through some problems have arisen. Namely, in prior art systems, theincoming water replacing the outgoing “hotter” rinsing water generallyenters the tank in a relatively turbulent, uncontrolled manner. Thisincoming water disrupts the temperature gradient in the tank therebydetrimentally effecting the temperature consistency of the outgoingwater. Therefore, in order to provide heated water at the desiredtemperature consistently, it would be desirable to control the incomingwater in a way in which the disruption of the stratified temperaturegradient in the tank is prevented. Preferably, the control of theincoming water can be handled in a manner that is relatively simple andinexpensive, which would not require the use of significant controlmeans, valves, etc., and which would help to provide water at thedesired temperature in a relatively efficient manner.

SUMMARY OF THE INVENTION

In accordance with the present invention, a method and apparatus forcontrolling incoming water flow into a water heating tank is provided.Specifically, the present invention provides a baffle for slowing theincoming water flow into a booster heating tank so that the turbulencein the water tank is minimized. More specifically, a baffle is providedwhich is of relatively simple construction, which is generallyinexpensive to produce, and which may be used in water boosters of thetype used in commercial warewashing applications. The baffle ischaracterized in that it comprises a cap including a water divertingmember, such as a flange, which depends downwardly from the edges of thecap. This water diverting member performs the critical task of divertingthe water that flows in the inlet backwards (generally downward in abooster having an inlet proximate the bottom of the water holding tankand an outlet substantially proximate the top portion of the waterholding tank) away from the outlet and the heating element.

In a preferred embodiment, the baffle of the present inventionpreferably consists of an inner cap and outer cap which are positionedover the inlet to a water heating tank. The inner cap is preferablyprovided with openings of varying shapes and sizes that are designed todirect the incoming flow of the water against the underside of the outercap. The outer cap is positioned over the inner cap and includes aflange that extends around the outer edges thereof. The outer cap isspaced apart from the inner cap such that the incoming water flowsthrough the openings in the inner cap and is directed to the undersideof the outer cap. The water, having been sufficiently slowed by thecontact with the underside of the outer cap, then flows downward alongthe outer cap flange and into the main plenum of the tank. Thepositioning of the flange is such that direct movement of the water fromthe underside of the cap along the walls of the water tank and out theoutlet is prevented thus insuring that the “hotter” water above theheater is removed from the tank first, leaving the “cooler” water tocontinue to heat in preparation for the next cycle of the warewasher. Aswill be discussed in greater detail below, use of the baffle of thepresent invention in the manner herein described has resulted in abetter, more consistent temperature gradient in the booster output watertemperature, thereby increasing the energy efficiency and utility of thewater boosters in which it has been implemented.

In a preferred embodiment, the inner and outer caps could be configuredfrom round or square tubing. A cost effective method is representedherein wherein a flat sheet of metal can be laser cut efficiently andrelatively inexpensively. The cut sheet then can simply be formed orfolded from the flats.

As stated herein, the principal object of the invention is to provide animprovement in water heating boosters which aids in providing heatedwater to a downstream user having a relatively consistent temperaturegradient, in an efficient manner. It is to be understood that while thespecification primarily refers to water as being the substance beingre-directed by the baffle of the present invention, the baffle could beused to divert and control the flow of other fluids, and this use wouldbe considered within the scope of the present invention. Other objectsand advantages will become apparent from the following description, inwhich reference is made to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a partial schematic view of a water heating tank for use inaccordance with the present invention;

FIG. 2 is a side perspective view of a baffle for use in accordance withthe present invention;

FIG. 3 is a side perspective view of the inner cap of the baffle of FIG.2;

FIG. 4 is a side elevational view of the baffle of FIG. 2;

FIG. 5 is a side elevational view of the baffle of FIG. 2 taken alongline A—A of FIG. 4;

FIG. 6 is a top plan view of the inner cap of the baffle of FIG. 2;

FIG. 7 is a top plan view of the outer cap of the baffle of FIG. 2;

FIG. 8 is a side elevational view of an alternate embodiment of theinvention;

FIG. 9 is a side elevational view of an alternate embodiment of theinvention; and

FIG. 10 is a graph of booster outlet temperature vs. time in a prior artbooster not utilizing a baffle in conformance with the presentinvention; and

FIG. 11 is a graph of booster outlet temperature vs. time in a novelbooster utilizing a baffle in conformance with the present invention.

DETAILED DESCRIPTION

Referring to FIG. 1, the apparatus and method of the present inventionis preferably used in a water heating tank, generally designated 10.While a generally annular tank 10 is preferred, the tank may also beother suitable shapes, including saddle shaped, rectangular shaped, etc.The tank 10 preferably includes a water inlet 12 near the bottom of thetank 10, a water outlet 14 near the top of the tank 10 and a heatingelement 16. A baffle assembly, generally designated 20, is positionedover the water inlet 12 in order to re-direct and slow the flow of waterentering the tank 10 so that the turbulence in the tank 10 is minimized.The baffle assembly 20 is preferably of relatively simple construction,is generally inexpensive to produce, and may be used in water boostersof the type used in commercial warewashing applications.

In a preferred embodiment, as shown best in FIGS. 2-7, the baffleassembly 20 is positioned over the inlet 12 to the water heating tank 10and consists of an inner cap 22 and an outer cap 24. The inner cap 22 ispreferably a collar-like base 26 with a cover 28 attached to the topportion of the base 26. The cover 28 is preferably provided withopenings 30 which may be of varying shapes and sizes, although in thepreferred embodiment shown herein as best seen in FIGS. 3 and 6, theopenings 30 are generally trapezoidal in shape.

As shown best in FIGS. 2 and 5, the outer cap 24 preferably consists ofa cover 32 and a flange 34 which depends downwardly from the cover 32around the base 26 of the inner cap 22. The outer cap 24 is positionedabove and spaced apart from the inner cap 22 such that water from theinlet 12 may flow through the openings 30 and impinge against the bottomof the cover 32 of the outer cap 24. The water then flows relativelysmoothly along the inside of the flange 34 and out into the tank 10. Theouter cap 24 is preferably attached to the inner cap 22 by a rod or bolt36 which is attached to the cover 32 of the outer cap 24 through hole 38and through the cover 28 of the inner cap 22 through hole 40. While thismethod of attaching and spacing apart the inner 22 and outer 24 caps isshown and described in the preferred embodiment, it is to be understoodthat other structures, including brackets or posts attached directly tothe inside of the tank 10 could be used to support the outer cap 24above the inner cap 22 and are considered within the scope of theinvention.

As shown best in FIG. 8, in an alternate embodiment of the invention,the baffle assembly 20B consists of an outer cap 24B having a flange 34Bthat depends downwardly therefrom. In this embodiment, the inlet 12includes an inlet pipe 50 which extends at least partially into the tank10. A bracket 52 including a spacer element 54 is used to position theouter cap 24B over the inlet pipe 50 thereby deflecting the incomingwater away from the tank 10 outlet (not shown). In a preferred versionof this embodiment, an inner cap 22B having perforations therein isprovided to help control fluid flow into the tank 10.

As shown best in FIG. 9, in another alternate embodiment of theinvention, the baffle assembly 20C consists of an outer cap 24C having aflange 34C that depends downwardly therefrom. In this embodiment, abracket 60 is used to position the outer cap 24C over the inlet 12thereby deflecting the incoming water away from the tank 10 outlet (notshown). In a preferred version of this embodiment, an inner cap 22Chaving perforations therein is provided to help control fluid flow intothe tank 10.

As shown in FIGS. 10 and 11, water booster heaters incorporating abaffle in accordance with the present invention have shown significantimprovement in temperature control for booster outlet temperature.Specifically, as can be seen in FIG. 10, prior art boosters notincorporating an inlet baffle in accordance with the present invention,exhibit large temperature fluctuations of booster outlet temperaturesover cycle time. In contrast, as shown in FIG. 11, water booster heatersincorporating an inlet baffle as described herein exhibit booster outlettemperature having little fluctuation over cycle time.

While the form of the apparatus herein described constitutes a preferredembodiment of the invention, it is to be understood that the inventionis not limited to this precise form of apparatus, and that changes maybe made therein without departing from the scope of the invention.

1. A fluid heating tank comprising: a fluid heating tank laying on itsside and having an inlet located in an annular sidewall of said tank ata lower portion of said tank and an outlet located at an upper portionof said tank higher than said inlet; and a baffle assembly positionedwithin said tank over said inlet, said baffle assembly comprising: aninner cap positioned over said inlet including a collar-like base havingan inner cover attached to the top portion of said base said inner coverhaving openings therein to control fluid flow into said tank; and anouter cap attached to and spaced apart from said inner cap by a spacer,said outer cap having a flange depending downwardly therefrom such thatwater flowing through said inlet may flow through said openings andimpinge against a bottom of said outer cap continuing relativelysmoothly along the inside of said flange and out into said tank.
 2. Thefluid heating tank of claim 1 wherein said flange at least partiallysurrounds said inner cap.
 3. The fluid heating tank of claim 1 whereinsaid openings and trapezoidal in shape.
 4. The fluid heating tank ofclaim 1 wherein said outer cap is generally square in shape.
 5. Thefluid heating tank of claim 1 wherein said inner cap is generally squarein shape.
 6. The fluid heating tank of claim 1 wherein said tank is awater heating booster for use with a commercial warewasher.
 7. A fluidheating tank comprising: a fluid heating tank laying on its side andhaving an inlet located in an annular sidewall of said tank at a lowerportion of said tank and an outlet located at an upper portion of saidtank higher than said inlet; and a baffle assembly positioned withinsaid tank over said inlet, said baffle assembly comprising: an inner cappositioned over said inlet including a collar-like base having an innercover attached to the top portion of said base, said inner cover havingopenings therein to control fluid flow into said tank; and an outer cappositioned over said inner cap wherein said outer cap is supported bybrackets depending from said sidewall of said tank, said outer caphaving a flange depending downwardly therefrom such that water flowingthrough said inlet may flow through said openings and impinge against abottom of said outer cap continuing relatively smoothly along the insideof said flange and out into said tank.
 8. A fluid heating tankcomprising: a fluid heating tank laying on its side and having an inletpipe with an end terminating at a lower portion of said tank, an outletlocated at an upper portion of said tank higher than said end of saidpipe; and a baffle assembly positioned within said tank over said end ofsaid pipe and adjacent an annular sidewall of said tank, said baffleassembly comprising: an inner cap positioned over said end of said pipeand including a collar-like base having an inner cover attached to thetop portion of said base, said inner cover having openings therein tocontrol fluid flow into said tank; and an outer cap positioned over andspaced apart from said inner cap, said outer cap having a flangedepending downwardly therefrom such that water flowing through said endof said pipe may flow through said openings and impinge against a bottomof said outer cap continuing relatively smoothly along the inside ofsaid flange and out into said tank.
 9. The fluid heating tank of claim 8wherein said flange at least partially surrounds said inner cap.
 10. Afluid heating tank comprising: a fluid heating tank laying on its sideand having an inlet pipe with an end terminating at a lower portion ofsaid tank, an outlet located at an upper portion of said tank higherthan said end of said pipe; and a baffle assembly positioned within saidtank over said end of said pipe, said baffle assembly comprising: aninner cap positioned over said end of said pipe and including acollar-like base having an inner cover attached to the top portion ofsaid base, said inner cover having openings therein to control fluidflow into said tank; and an outer cap attached to and spaced apart fromsaid inner cap by a spacer, said outer cap having a flange dependingdownwardly therefrom such that water flowing through said end of saidpipe may flow upward through said openings and impinge against a bottomof said outer cap continuing relatively smoothly downward along theinside of said flange and out into said tank.